Cooler flusher

ABSTRACT

Method and apparatus for servicing a vehicle&#39;s transmission cooling system, where the apparatus includes a source valve with inlet and outlet ports, a pump with inlet and outlet ports, and a return valve with inlet and outlet ports. The pump inlet is connected to the source valve outlet. The pump pumps fluid from the source valve inlet through the source valve outlet and the pump inlet to the pump outlet for servicing the transmission cooling system. The fluid returns from the return valve inlet to the return valve outlet and the pump then re-pumps the fluid into the transmission cooling system. The service apparatus may also include a fluid source and a filter interposed between the fluid source and the source valve, where the fluid returns to the fluid source prior to re-pumping the fluid. The service apparatus may also include a flowmeter interposed between the return valve and the fluid source and a filter interposed between the return valve and the flowmeter.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to the field of vehicle maintenance andrepair. More specifically, the invention is directed to servicingtransmission cooling systems.

2. Related Art

It is common for vehicles with automatic transmissions to have a coolingsystem for the transmission fluid in order to keep the operatingtemperature of the transmission within a desired range. Most cars,especially larger models, have such a transmission cooling system. Mosttrucks and vans require a larger transmission cooling system to handleextra stress placed on the transmission by, for example, carrying heavyloads or towing trailers. A typical transmission cooling system isconnected to the transmission in such a way that transmission fluid iscirculated from the transmission to a transmission fluid cooler throughone line, then circulated through the transmission fluid cooler, andreturned to the transmission through a second line.

A transmission cooling system can include, for example, a transmissionfluid cooler inside the vehicle's radiator, so that the transmissionfluid cooler is immersed in the engine coolant inside the radiator.Thus, engine coolant, typically a combination of water and antifreeze,flows over the outside of the transmission fluid cooler whiletransmission fluid flows on the inside of the transmission fluid cooler.Heat is transferred from the transmission fluid circulating inside thetransmission fluid cooler to the engine coolant circulating outside thetransmission fluid cooler. Air flow over the outside of the radiatorcools the engine coolant. Other cooling devices may also be used, forexample, a device called a “heat exchanger” may be used in conjunctionwith or instead of the transmission fluid cooler described above. Thetransmission fluid cooler is also sometimes referred to as atransmission “oil cooler.” A common design among all these devices isthat each circulates fluid from the transmission through the device, inorder to cool the fluid, and then returns the cooled fluid to thetransmission. Thus, in a transmission cooling system, transmission fluidis circulated from the vehicle's transmission system, through atransmission fluid cooler which controls the temperature of thetransmission fluid, and returns to circulate through the transmission,thereby keeping the transmission within desired operating temperaturerange.

For various reasons such as extended use of the vehicle or transmissionfailure, the transmission fluid can become “dirty” or contaminated withdebris, for example, metal flakes from worn parts inside thetransmission. Such debris can accumulate inside the transmission coolingsystem, in particular, inside the transmission cooler causing it to“clog” or become incapable of sufficient circulation of transmissionfluid to provide adequate cooling. Occasionally, a transmission coolerbecomes so clogged that it must be replaced. Transmission cooling systemclogging can also lead to premature transmission failure. It is,therefore, crucial to clean the transmission cooling system as part ofnormal periodic transmission servicing. In addition, when a transmissionis removed to be rebuilt or replaced with a new or rebuilt transmission,the transmission cooling system is typically cleaned to avoidcontamination of the reinstalled transmission.

A number of conventional means are available for cleaning transmissioncooling systems. One conventional means uses a pressurized containercontaining a liquid cleaner, for example, a can containing compressedsolvent. Use of such means has many disadvantages. For example, theamount of cleaning that can be performed is limited by the amount ofsolvent and the can pressure, which may require the use and expense ofextra cans. In addition, the cleaning liquid is only used once, which iswasteful because cleaning liquid is typically not completely dirty afteronly one use and can be used again. Disposing cleaning liquid which iscapable of being reused is not only wasteful, but is also harmful to theenvironment.

Another disadvantage of using a compressed solvent can is that it doesnot provide a measure of the effectiveness of the cleaning. As a result,a transmission fluid cooler, which appears to have been cleaned maystill be incapable of sufficient circulation of transmission fluid toprovide adequate cooling, but may be reused and cause transmissionoverheating and damage.

Other conventional methods of cleaning transmission cooling systems mayuse air pressure. A source of such air pressure may be a pressurizedsystem of air hoses commonly found in auto repair shops, typicallyreferred to as “shop air,” typically at a pressure of 100.0 to 120.0pounds per square inch (“psi”). Use of such methods is disadvantageousin that shop air may not be available at the location where the vehicleis to be serviced. Further, high air pressure can present safetyconcerns for the operators. In addition, shop air methods suffer fromother disadvantages, such as using the cleaning liquid only once, whichis wasteful because cleaning liquid is typically not completely dirtyafter only one use and can be used again. As stated above, suchwastefulness is also harmful to the environment.

Accordingly, there is an intense need in the art for a new coolerflusher method and apparatus that can overcome the disadvantages anddrawbacks in the conventional art; that can improve cost, efficiency,and safety; and that can remove environmental concerns.

SUMMARY OF THE INVENTION

In accordance with the purpose of the present invention as broadlydescribed herein, there is provided method and apparatus for servicing avehicle's transmission cooling system.

In one aspect of the present invention, a service apparatus, forservicing a vehicle's transmission cooling system, includes a sourcevalve with inlet and outlet ports, a pump with inlet and outlet ports,and a return valve with inlet and outlet ports. The pump inlet isconnected to the source valve outlet. The pump pumps fluid from thesource valve inlet through the source valve outlet and the pump inlet tothe pump outlet for servicing the transmission cooling system. The fluidreturns from the return valve inlet to the return valve outlet and thepump then re-pumps the fluid into the transmission cooling system.

In another aspect, the service apparatus further includes a fluid sourceand a filter interposed between the fluid source and the source valve.In yet another aspect, the fluid returns to the fluid source prior tore-pumping the fluid. In one aspect, the service apparatus also includesa flowmeter interposed between the return valve and the fluid source anda filter interposed between the return valve and the flowmeter.

In one aspect of the present invention, the source valve inlet may alsofunction as an air inlet. In yet another aspect, the source valveincludes an air inlet and the return valve includes a waste outlet.

The service apparatus of the present invention can be used to perform aservice method comprising the steps of pumping air into an inlet port oftransmission cooling system to cause transmission fluid to flow out ofan outlet port of the transmission cooling system; cycling a solventthrough the transmission cooling system, where the solvent entersthrough the inlet port and exits through the outlet port of thetransmission cooling system; re-cycling the solvent exiting through theoutput port through the transmission cooling system; and pumping airinto the inlet port to cause the solvent in the transmission coolingsystem to exit through the outlet port.

These and other aspects of the present invention will become apparentwith further reference to the drawings and specification, which follow.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A illustrates a front view of a cooler flusher system according toone embodiment of the present invention;

FIG. 1B illustrates a left side view of the cooler flusher system ofFIG. 1A;

FIG. 1C illustrates a right side view of the cooler flusher system ofFIG. 1A;

FIG. 1D illustrates an example control panel of the cooler flushersystem of FIG. 1A;

FIG. 2 illustrates a fluid flow schematic diagram of the cooler flushersystem of FIG. 1A;

FIG. 3 illustrates a flowchart of the steps used to service atransmission cooling system using the cooler flusher system of FIG. 1A;and

FIG. 4 illustrates an electrical schematic diagram of the cooler flushersystem of FIG. 1A.

DETAILED DESCRIPTION OF THE INVENTION

The following description contains specific information pertaining tothe implementation of the present invention. One skilled in the art willrecognize that the present invention may be implemented in a mannerdifferent from that specifically discussed in the present application.Moreover, some of the specific details of the invention are notdiscussed in order to not obscure the invention. The specific detailsnot described in the present application are within the knowledge of aperson of ordinary skill in the art.

The drawings in the present application and their accompanying detaileddescription are directed to merely example embodiments of the invention.To maintain brevity, other embodiments of the invention which use theprinciples of the present invention are not specifically described inthe present application and are not specifically illustrated by thepresent drawings.

FIG. 1A shows a cooler flusher system according to one embodiment of thepresent invention. FIGS. 1A, 1B, and 1C show cooler flusher system 100from the front and also from a left side view and a right side view forgreater clarity. As shown in Figure 1A, cooler flusher system 100includes pressure hose 102 for delivering solvent or air under pressureto a transmission cooling system (not shown). Pressure is supplied froma pump internal to cooler flusher system 100, discussed in more detailbelow with reference to FIG. 2. The solvent can be, for example, mineralspirits or commercially available biodegradable soap-like solution, orany other suitable cleaning fluid. Cooler flusher system 100 alsoincludes return hose 104 for the return of fluid, either transmissionfluid or solvent, from the transmission cooling system. The fluidreturned from the transmission cooling system through return hose 104can be directed to waste hose 106 or to fluid tank 108. Contaminatedfluid, for example, debris-laden transmission fluid, is directed throughwaste hose 106 to a receptacle for disposal. Reusable fluid, forexample, solvent, is directed to fluid tank 108.

Cooler flusher system 100 further includes filters 112 and 114. Filter112 filters solvent before it is delivered to pressure hose 102. Filter112 can be a relatively fine filter, i.e. one which traps all particlesgreater than some small size, such as a paper filter or a fine screenmesh. Filter 114 filters solvent after it is returned through returnhose 104. Filter 114 can be a relatively coarse filter, i.e. one whichtraps particles of greater size than the paper filter is designed for,such as a screen filter. The purpose of filter 114 is to provide afilter that is less susceptible to clogging and which, therefore, needscleaning or replacing less often. Further, filter 114 filters out largersize particles from the solvent stream that passes through filter 112.Filters 112 and 114 will keep the solvent clean for longer use andprevent premature failure of cooler flusher system 100. Cooler flushersystem 100 also includes power cables 116 for supplying power to thepump. Cooler flusher system 100 also includes front panel 120.

Referring now to Figure 1D, front panel 120 of Figure 1A is shown inmore detail. As seen in Figure 1D, front panel 120 includes source valve122 for directing flow to pressure hose 102 from either of fluid tank108 or an air inlet check valve (not shown in Figure 1D). Source valve122 is also provided with an “off” position which prevents flow throughsource valve 122. Front panel 120 also includes return valve 124 fordirecting flow from return hose 104 to either of waste hose 106 or fluidtank 108. Return valve 124 is also provided with an “off” position whichprevents flow through return valve 124. Front panel 120 also includesflow meter 128 for measuring flow of fluid through the transmissioncooling system. Figure 1D also shows that control panel 120 includespower switch 132, indicator light 134, and circuit breaker 136. Powerswitch 132, indicator light 134, and circuit breaker 136 are discussedin more detail below with reference to FIG. 4.

Flow diagram 200 of FIG. 2 illustrates pressure hose 202 of coolerflusher system 100 connected to transmission cooling system 201 viahydraulic connector 203. Return hose 204 of cooler flusher system 100 isconnected to transmission cooling system 201 via hydraulic connector205. Hydraulic connectors 203 and 205 can be standard connectors asknown in the art or other means such as hoses and clamps. Pressure hose202 can be any hose capable of supporting the pressure delivered by pump238. For example, typical pressure is in the range of approximately 15.0psi (pounds per square inch) to 50.0 psi. Return hose 204 may be anysuitable hose for returning transmission fluid or solvent fromtransmission cooling system 201.

Return hose 204 delivers fluid to return valve 224 for directing flowfrom return hose 204 to either of waste hose 206 or fluid tank 208. Forexample, return valve 224 can be a three-way valve with an “off”position, an “evacuate” position, and a “flush” position. In oneembodiment, the three-way valve may include one inlet port and twooutlet ports. As shown, the inlet port of return valve 224 may receivefluid from transmission cooling system 201, which fluid may then flowout of either of the outlet ports depending on the position of returnvalve 224. The “off” position can be used to prevent all flow throughvalve 224; the “evacuate” position can be used to direct flow fromreturn hose 204 to waste hose 206 when removing transmission fluid fromtransmission cooling system 201; and the “flush” position can be used todirect flow from return hose 204 to fluid tank 208 when pumping solventfrom fluid tank 208, through transmission cooling system 201, and backto fluid tank 208. Waste hose 206 can be any suitable hose fordelivering transmission fluid from return valve 224 to a waste orrecycling receptacle. Fluid tank 208 can be any suitable container forholding the solvent or other cleaning fluid used to clean transmissioncooling system 201.

In one embodiment, filter 214 and flow meter 228 are interposed betweenreturn valve 224 and fluid tank 208. For example, filter 214 can be ascreen filter for filtering coarse size particles from the solvent asdiscussed above. Flow meter 228 can be any device capable of measuringthe flow of solvent through transmission cooling system 201 andproviding a satisfactory read out to an operator.

Continuing with FIG. 2, flow diagram 200 shows source valve 222 fordirecting flow to pump 238 from either of fluid tank 208 or check valve240. For example, source valve 222 can be a three-way valve with an“off” position, an “air/recover” position, and a “flush” position. Inone embodiment, the three-way valve may include two inlet ports and anoutlet port, where one inlet may provide air and the other provideliquid or fluid. As shown, the outlet port of source valve 222 isconnected to an inlet of pump 238, which can pump fluid or air frominlet of pump 238 to an outlet of pump 238. The “off” position can beused to prevent all flow through source valve 222; the “air/recover”position can be used to direct air flow from check valve 240 to pump 238when removing transmission fluid from transmission cooling system 201;and the “flush” position can be used to direct liquid flow from fluidtank 208 to pump 238 when pumping solvent from fluid tank 208, throughtransmission cooling system 201, and back to fluid tank 208. Check valve240 can be any suitable one-way flow device for allowing a flow of airinto source valve 222 and preventing any backflow of fluid from sourcevalve 222 and out of cooler flusher system 100. Thus, the “air/recover”position of source valve 222 can be used to direct a flow of air fromcheck valve 240 to pump 238 when removing transmission fluid fromtransmission cooling system 201. In an alternative mode of operation,the “flush” position of source valve 222 can be used to direct a flow ofsolvent from fluid tank 208 to pump 238 when removing larger amount oftransmission fluid from transmission cooling system 201.

Flow diagram 200 further shows pump 238 for supplying pressure for flowof air or fluid through cooler flusher system 100 and transmissioncooling system 201. In one embodiment, filter 212 is interposed betweenfluid tank 208 and source valve 222. For example, filter 212 can be apaper filter for filtering fine size particles from the solvent asdiscussed above.

FIG. 3 shows flowchart 300 for describing example steps for cleaning atransmission cooling system 201 using cooler flusher system 100. Certaindetails and features, which are apparent to a person of ordinary skillin the art, have been left out of flowchart 300, for example, a step mayconsist of one or more sub-steps or may involve specialized tools, asknown in the art.

As shown in FIG. 3, step 302 of flowchart 300 comprises disconnectingtransmission cooling system 201 from a vehicle's transmission. Forexample, the transmission fluid lines may both be disconnected at theoil cooler of transmission cooling system 201. Subsequent to step 302,inlet and outlet ports of transmission cooling system 201 are availablefor connecting to pressure hose 102 and return hose 104 of coolerflusher system 100.

Step 304 of flowchart 300 comprises connecting cooler flusher system 100to transmission cooling system 201. Pressure hose 202 may be connectedto either inlet port or outlet port of transmission cooling system 201using hydraulic connector 203. Return hose 204 is connected to the otherport of transmission cooling system 201 using hydraulic connector 205.Thus, subsequent to step 304, transmission cooling system 201 has itsinlet port connected to pressure hose 202 and its outlet port connectedto return hose 204 of cooler flusher system 100.

Next, in step 306, cooler flusher system 100 is connected to a source ofelectrical power and waste-hose 206 is directed to a suitablereceptacle. For example, power cables 116 of cooler flusher system 100shown in FIG. 1A can be connected to the vehicle's battery. Power cables116 may also be connected, for example, to any automobile battery orpower source. The free end of waste hose 206 can be placed, for example,in an auto service shop's hydraulic fluid recycling receptacle.Subsequent to step 306 of flowchart 300, then, cooler flusher system 100is connected to a source of power for pump 238 of cooler flusher system100, waste hose 206 is properly placed for collection of transmissionfluid, and cooler flusher system 100 is connected to transmissioncooling system 201 so that cleaning of transmission cooling system 201may commence.

Step 308 of flowchart 300 comprises setting source valve 222 and returnvalve 224 to configure cooler flusher system 100 for evacuatingtransmission fluid from transmission cooling system 201. Return valve224 is set to the “evacuate” position to direct flow from return hose204 to waste hose 206. Source valve 222 is then set to the “air/recover”position to direct a flow of air into pressure hose 202. Power switch132, shown in Figure 1D, is then set to the “on” position to start pump238 of cooler flusher system 100. The pump can be run for a sufficientlength of time to remove substantially all the transmission fluid fromtransmission cooling system 201. For example, waste hose 206 can be madeof a transparent material suitable for viewing whether transmissionfluid or air is flowing through waste hose 206. When it is clear thatsubstantially all transmission fluid has been removed from transmissioncooling system 201, power switch 132 is set to the “off” position tostop pump 238 of cooler flusher system 100.

If, during step 308 of flowchart 300, it becomes apparent that the flowof pressurized air is insufficient to satisfactorily evacuatetransmission fluid from transmission cooling system 201, an alternativemode of operation of cooler flusher system 100 may be followed.Observation of whether flow of pressurized air is insufficient tosatisfactorily evacuate transmission fluid from transmission coolingsystem 201 is illustrated in flowchart 300 by decision step 310. Thealternative mode of operation is shown in flowchart 300 as step 312. Atstep 310, if it is observed that flow of pressurized air is sufficientto satisfactorily evacuate transmission fluid from transmission coolingsystem 201, then cleaning of transmission cooling system 201 proceedswith step 314 directly after step 308. If, at step 310, it is observedotherwise that flow of pressurized air is insufficient to satisfactorilyevacuate transmission fluid from transmission cooling system 201, thencleaning of transmission cooling system 201 can proceed with step 312directly after step 308.

Step 312 of flowchart 300 comprises setting source valve 222 to the“flush” position to direct a flow of solvent into pressure hose 202. Itshould be noted that return valve 224 is already set to the “evacuate”position to direct flow from return hose 204 to waste hose 206 as partof step 308. Power switch 132 is then set to the “on” position to startpump 238 of cooler flusher system 100. Pump 238 can be run for asufficient length of time to remove substantially all the transmissionfluid from transmission cooling system 201. When it is observed, forexample, by viewing through transparent waste hose 206, thatsubstantially all transmission fluid has been removed from transmissioncooling system 201, power switch 132 is set to the “off” position tostop pump 238 of cooler flusher system 100. Accordingly, after step 308,or alternatively, after steps 308 and 312, transmission cooling system201 has been substantially cleared of transmission fluid and is readyfor cleaning.

Step 314 of flowchart 300 comprises setting source valve 222 and returnvalve 224 to configure cooler flusher system 100 for cleaningtransmission cooling system 201 by flushing it with solvent. Returnvalve 224 is set to the “flush” position to direct flow from return hose204 to fluid tank 208. Source valve 222 is then set to the “flush”position to direct a flow of fluid from fluid tank 208 to pressure hose202. Power switch 132 is then set to the “on” position to start pump 238of cooler flusher system 100. Solvent is then continuously cycledthrough transmission cooling system 201 and fluid tank 208 of coolerflusher system 100. Pump 238 of cooler flusher system 100 can be run fora sufficient length of time to remove substantially all contaminationand blockage from transmission cooling system 201. For example, a periodof 5 to 10 minutes has been determined to be sufficient in most cases toadequately clean a typical transmission cooling system. An alternativeto using a predetermined period of time for running pump 238 of coolerflusher system 100 is to measure the flow of solvent through flow meter228 and stop pump 238 according to various methods utilizing suchmeasurement. For example, one method is to measure improvement in theflow through flow meter 228. As long as flow is improving, i.e.increasing, solvent is cycled through transmission cooling system 201.When improvement of flow slows substantially or stops, that is taken asan indication that no more improvement is to be had, and therefore,transmission cooling system 201 has been cleaned. Another method, forexample, may be to measure the numerical value of flow of solventthrough flow meter 228 and compare that value to a specification for theparticular transmission cooling system at hand. Typical specificationvalues for flow through transmission cooling systems are in the range ofapproximately 1.0 to 2.0 gallons per minute. If flow is below thespecification, then solvent is cycled through transmission coolingsystem 201. If flow is satisfactorily close to the specification, thenthat is taken as an indication that transmission cooling system 201 hasbeen cleaned. Thus, measurement of the flow of fluid throughtransmission cooling system 201 can provide indications, for example, ofhow much time is required to clean transmission cooling system 201,whether transmission cooling system 201 is adequately clean, or whetherportions of transmission cooling system 201, such as the oil cooler,need to be replaced. When it has been decided that transmission coolingsystem 201 has been cleaned or, alternatively, that transmission coolingsystem 201 cannot be adequately cleaned and needs to be replaced, powerswitch 132 is set to the “off” position to stop pump 238 of coolerflusher system 100. Subsequent to step 314 of flowchart 300,transmission cooling system 201 contains solvent which should berecovered to fluid tank 208 of cooler flusher system 100.

Step 316 of flowchart 300 comprises setting source valve 222 and returnvalve 224 to configure cooler flusher system 100 for recovering solventfrom transmission cooling system 201. Return valve 224 is set to the“flush” position to direct flow from return hose 204 to fluid tank 208.Source valve 222 is set to the “air/recover” position to direct a flowof air into pressure hose 202. Power switch 132 is set to the “on”position to start pump 238 of cooler flusher system 100. Pump 238 can berun for a sufficient length of time to recover substantially all thesolvent from transmission cooling system 201. When it is clear thatsubstantially all solvent has been recovered from transmission coolingsystem 201, power switch 132 is set to the “off” position to stop pump238 of cooler flusher system 100. Subsequent to step 316 of flowchart300, transmission cooling system 201 has been cleaned or it has beendecided that transmission cooling system 201 is no longer fit forservice. In either case, cooler flusher system 100 is disconnected fromtransmission cooling system 201, and from the vehicle's battery if thatwas used. If transmission cooling system 201 is fit for service, afurther step may be taken, for example, of flushing a small amount oftransmission fluid through transmission cooling system 201 to removeresidual solvent, which may be present after completion of step 316 offlowchart 300, before reconnecting transmission cooling system 201 tothe transmission on the vehicle. Thus, after completion of step 316 offlowchart 300, transmission cooling system 201 is reconnected to thevehicle or a replacement transmission cooling system is provided.

Referring now to FIG. 4, electrical schematic diagram 400 is shown forone embodiment of the present invention. Electrical schematic diagram400 shows electrical connections of components for supplying electricpower to the pump of cooler flusher system 100 according to oneembodiment of the present invention.

As shown in FIG. 4, power cables 416 in electrical schematic 400 areconnected to a source of electrical power suitable for operating pump438 at the desired operating capacity. For example, the source ofelectrical power can be a car battery, as discussed above. Electricalschematic 400 also shows power switch 432 for controlling pump 438.Thus, pump 438 can be started by moving the position of switch 432 from“off” to “on” or stopped by moving the position of switch 438 from “on”to “off.” Diagram 400 also shows indicator light 434 wired in serieswith switch 432 so that indicator light 434 is lit whenever switch 432is in the “on” position. Indicator light 434 provides a safety featurefor the operator to know whether power is connected when switch 432 isin the on position. Indicator light 434, for example, can be a very lowpower amber lamp. Switch 432 is isolated from pump 438 by relay 435 in astandard manner. Thus, switch 432 can be, for example, a toggle switchcapable of handling enough power to power relay 435 and indicator light434. Relay 435 can be, for example, a simple relay capable of handlingenough power to power pump 438. Electrical schematic 400 also showscircuit breaker 436 wired in series with the source of electrical powerin order to protect all electrical components of electrical schematic400. Circuit breaker 436, for example, can be a fuse of a proper ratingor a standard switch type circuit.

Thus, according to one embodiment of the present invention, coolerflusher system 100 provides a means for cleaning transmission coolingsystems in which the cleaning fluid or solvent can be repeatedly andcontinuously flushed through the transmission cooling system in order toensure adequate cleaning. Because of the cycling of solvent, coolerflusher system 100 provides flexibility in that the amount of cleaningcan be adjusted to each particular transmission cooling system byadjusting the amount of time that solvent is cycled through atransmission cooling system. For example, a dirtier transmission coolingsystem may require, and can receive, more cleaning by cycling solventfor a longer period of time. Moreover, because of cycling the solvent,cooler flusher system 100 provides more economical cleaning in that thesame solvent can be effectively used for many vehicles. Cycling ofsolvent also avoids other disadvantages of using the cleaning liquidonly once, for example wastefulness. Using the cleaning liquid only oncecan be wasteful because cleaning liquid is typically not completelydirty after only one use and can be used again. Reuse of cleaning fluidthrough cycling of solvent avoids premature disposal of cleaning fluid,which is beneficial to the environment.

Various techniques may be used for implementing the concepts of thepresent invention without departing from its scope. While the presentinvention has been described with specific reference to certainembodiments, a person of ordinary skills in the art would recognize thatchanges can be made in form and detail without departing from the spiritand the scope of the invention. The described embodiments are to beconsidered in all respects as illustrative and not restrictive. Itshould also be understood that the invention is not limited to theparticular embodiments described herein, but is capable of manyrearrangements, modifications, and substitutions without departing fromthe scope of the invention.

What is claimed is:
 1. A service apparatus comprising: a first valvehaving a first inlet, a second inlet and a first outlet; a pump having apump inlet and a pump outlet, wherein said pump inlet is connected tosaid first outlet of said first valve and said pump outlet is capable ofbeing connected to a first hose; a second valve having a first inlet, afirst outlet and a second outlet, wherein said first inlet of saidsecond valve is capable of being connected to a second hose; and a flowmeter having a flow meter inlet and a flow meter outlet, wherein saidflow meter inlet is connected to said first outlet of said second valveand said flow meter outlet is connected to said first inlet of saidfirst valve.
 2. The service apparatus of claim 1, wherein said firstvalve is set such that said pump pumps air from said first inlet of saidfirst valve through said first outlet of said first valve to said firsthose.
 3. The service apparatus of claim 2, wherein said first hose isconnected to an inlet of a system and said second hose is connected toan outlet of said system, and wherein said air from said first hoseenters said system inlet and causes fluid in said system to flow out ofsaid system outlet to said second hose.
 4. The service apparatus ofclaim 3, wherein said fluid flows from said second hose into said firstinlet of said second valve, and wherein said second valve is set suchthat said fluid flows out of said first outlet of said second valve. 5.The service apparatus of claim 4, wherein said fluid flowing out of saidfirst outlet of said second valve is disposed.
 6. The service apparatusof claim 1, wherein said first valve is set such that said pump pumps afluid from said second inlet of said first valve through said firstoutlet of said first valve to said first hose.
 7. The service apparatusof claim 6, wherein, through second hose, said fluid flows to said firstinlet of said second valve, and wherein said second valve is set suchthat said fluid flows out of said second outlet of said second valve andis re-pumped into said first hose by said pump.
 8. The apparatus ofclaim 7 further comprising a filter for filtering said fluid prior tore-pumping said fluid.
 9. An apparatus for servicing a system, saidapparatus comprising: a first valve having an inlet and an outlet; apump having an inlet and an outlet, wherein said pump inlet is connectedto said first valve outlet; a second valve having an inlet and anoutlet; and a flow meter having an inlet and an outlet, wherein saidflow meter inlet is connected to said second valve outlet and said flowmeter outlet is connected to said first valve inlet; wherein said pumppumps a fluid from said first valve inlet through said first valveoutlet and said pump inlet to said pump outlet for servicing saidsystem, and said fluid returns from said second valve inlet to saidsecond valve outlet and said flow meter inlet to said flow meter outlet,and wherein said pump re-pumps said fluid.
 10. The apparatus of claim 9futher comprising a fluid source.
 11. The apparatus of claim 10 furthercomprising a filter interposed between said fluid source and said firstvalve.
 12. The apparatus of claim 10 wherein said fluid returns to saidfluid source prior to re-pumping said fluid.
 13. The apparatus of claim9 further comprising a filter interposed between said second valve andsaid flowmeter.
 14. The apparatus of claim 9, wherein said system is atransmission cooling system.
 15. The apparatus of claim 9, wherein saidfirst valve inlet is capable of functioning as an air inlet.
 16. Theapparatus of claim 9, wherein said first valve further includes an airinlet.
 17. The apparatus of claim 9, wherein said second valve furtherincludes a waste outlet.
 18. An apparatus for servicing a system, saidapparatus comprising: a first valve having an inlet and an outlet; apump having an inlet and an outlet, wherein said pump inlet is connectedto said first valve outlet and said pump outlet is connected to an inletof said system; a second valve having an inlet and an outlet, whereinsaid second valve inlet is connected to an outlet of said system; a flowmeter having an inlet and an outlet, wherein said flow meter inlet isconnected to said second valve outlet; and a fluid source having aninlet and an outlet, wherein said fluid source inlet is connected tosaid flow meter outlet and said fluid source outlet is connected to saidfirst valve inlet; wherein said pump pumps a fluid from said first valveoutlet through said pump inlet through said pump outlet to said systeminlet for servicing said system, and said fluid returns from said systemoutlet to said second valve inlet to said second valve outlet and saidflow meter inlet to said flow meter outlet, and wherein said pumpre-pumps said fluid, and wherein said flow meter is capable of measuringflow of said fluid through said system.
 19. The apparatus of claim 18further comprising a filter interposed between said fluid source outletand said first valve inlet.
 20. The apparatus of claim 18, wherein saidfluid returns to said fluid source prior to re-pumping said fluid. 21.The apparatus of claim 18 further comprising a filter interposed betweensaid second valve outlet and said flow meter inlet.
 22. The apparatus ofclaim 18, wherein said system is a transmission cooling system.
 23. Theapparatus of claim 18, wherein said first valve inlet is capable offunctioning as an air inlet.
 24. The apparatus of claim 18, wherein saidfirst valve further includes an air inlet.
 25. The apparatus of claim18, wherein said second valve further includes a waste outlet.